Shadow mask supported by pin-shaped members retained in cavities in side walls of faceplate



J. H. DUISTERMAAT ET AL SUPPORTED BY PIN AVITIES IN SIDE W 3,497,746 SHAPED MEMBERS RETAINED ALLS OF FACEPLATE 2 Sheets-Sheet 1 Feb. 24, 1970 SHADOW MASK IN 0 Filed May 24, 1968 INVENTORS. JAN H. DUISTERMAAT I JOHANNES A. VAN LEUWEN GENT Feb. 24, 1970 J. H. DUISTERMAAT E L 3,497,746

SHADOW MASK SUPPORTED BY PIN-SHAPED MEMBERS RETAINED IN CAVITIES IN SIDE WALLS OF FACEPLATE Filed May 24, 1968 2 Sheets-Sheet 2 INVENTOR? JAN H.DUISTERMAAT JOHANNES A.VAN LEEUWEN United States Patent US. Cl. 313-85 4 Claims ABSTRACT OF THE DISCLOSURE In a color television cathode ray tube a plurality of resilient strips each have an end attached to the frame of a shadow mask and the opposite end attached to a mounting post substantially parallel to the longitudinal axis of the tube. The cathode ray tube faceplate has a similar plurality of shaped cavities to receive the mounting posts and thereby support the shadow mask.

The invention relates to a colour television display cathode-ray tube in which a substantially rectangular colour selection electrode is arranged in the proximity of the display screen and is supported by a plurality of supporting members which are secured on the one hand to the periphery of the colour selection electrode and are each supported on the other hand in a cavity provided in a thickened part of the glass tube wall. According to the invention, an accurate and readily detachable fastening of the colour selection electrode is obtained by providing each supporting member with resilient parts which press against the side Walls of the cavity and are clamped and fixed therein. The resilient parts may form part of a substantially pin-shaped body which is arranged parallel to the tube axis and is clamped and fixed in a cavity likewise extending parallel to the tub axis. If required, steps may be taken to ensure that, after the window and the cone of the bulb of the tube have been joined, the pin-shaped bodies are fixed in the cavities.

The invention will be described more fully with reference to the drawing, in which:

FIGURES 1, 2 and 3 show parts of a window of a cathode-ray tube according to the invention,

FIGURE 4 is an embodiment of a suspension member for a shadow mask,

FIGURE 5 is a sectional view of part of a cathode-ray tube after the window and the cone have been joined,

FIGURE 6 is a similar sectional view of another embodiment according to the invention, and

FIGURE 7 is an elevation of the open side of a cone of the embodiment of FIGURE 6.

In the figures, reference numeral 1 denotes a glass window to which a phosphor screen has to be applied which consists of dots of phosphors luminescing in three colours. The protruding edge of the window is provided with a thickened part or stud 3 which is pressed simultaneously with the window. A cavity 4 is pressed into the stud 3. This cavity may be substantially cylindrical (cf. FIGURE 2) or may have the form of a cylinder having a com- 3,497,746 Patented Feb. 24, 1970 ICC pletely uninterrupted wall; alternatively, the cavity may have a U-shaped cross-section as is indicated by 5 in FIG- URES 1, 3 and 5.

The shadow mask 6 secured on a frame 7 is supported in the protruding edge of the window 1 by means of resilient supporting members 8 which are provided in FIG- URE 1 with resilient parts 13 and in FIGURE 4 with a substantially pin-shaped body 9 having resilient parts 10. The thickened parts are preferably disposed at the corners of the window, especially with the use of a comparatively light mask which is not secured on a supporting frame 7, in order to increase the strength of the suspension.

The body 9 is arranged parallel to the tube axis, whilst the resilient tags 10 are received with clamping fit by the cavity 4, 5. The pin 9 may be hollow and may be secured to the supporting member 8 by a flanged edge 12. After the phosphor screen has been applied, the shadow mask 6 may be permanently fixed, for example, by screwing a screw bolt into the cavity of the flanged edge 12, as a result of which the resilient part 10 of the pin 9 expands and pressed against the side walls so that it is rigidly clamped in the cavity 4, 5. Alternatively, the glaze 11, by means of which the cone 2 is secured to the edge of the window 1, may be utilized to fix the pin 9 in the cavity 4, 5, as is shown in FIGURES 5 and 6.

By the use of substantially pin-shaped bodies 9, 10, the insertion and removal of the shadow mask during the application of the phosphor screen is considerably simplified, whilst after the pins 9 have been inserted into the cavities 4, 5, an accurate centering of the mask 6 relative to the screen is invariably obtained.

Two or more pin-shaped members may be prolonged so that they extend on either side of the supporting member 8, as is indicated by 14 and 15 in FIGURE 6. The part 15 of each of these pins may then be utilized to centre the cone with respect to the window when these parts are joined by means of the glaze 11. The part 15 of one pin is located, for example, in a cavity 16 and that of the other pin engages a fitting edge 18 provided in the glass wall of the cone 19, preferably during pressing of the cone.

External jigs are then no longer required for joining the window and the cone. The fitting edge 18 and the cavity 16 in the cone wall must have the same tolerances as the glass parts.

What is claimed is:

1. A colour television cathode ray tube comprising, a display screen having thereon a plurality of groups of phosphor dots and being positioned on the front wall of a faceplate having a substantially rectangular shape, a correspondingly shaped shadow mask proximate said display screen and having apertures aligned with said groups, a plurality of resilient strips attached to spaced portions of the frame of said shadow mask at one end and to substantially pin-shaped members at the other, said pinshaped members being substantially parallel to the longitudinal axis of said tube, said faceplate having thickened sidewall portions including shaped cavities to receive said pin-shaped resilient parts to press against the sidewalls of said cavities and clamp said members therein for fixedly supporting said shadow mask.

2. A cathode-ray tube as claimed in claim 1, wherein said resilient parts form part of a substantially pin-shaped body which is arranged parallel to the tube axis and is 3 clamped and fixed in a cavity likewise extending parallel to the tube axis.

3. A cathode-ray tube as in claim 1, wherein said pinshaped body is fixed in the cavity by means of a glaze by which the cone is joined to the window.

4. A cathode-ray tube as in claim 1, wherein said pinshaped body is fixed in the cavity by inserting an expansion screw.

.4 References Cited UNITED STATES PATENTS 2,795,719 6/1957 Morrell. 3,358,170 12/1967 Fiore.

ROBERT SEGAL, Primary Examiner US. Cl. X.R. 313-288 Patent No. 3 497 .746

Inventor(s) It is certified that error and that said Letters Patent Column 2, line line line

line 64,

Column 3, line line line

line

Signed and sealed this 23rd day of March 1971.

(SEAL) Attest:

change change change change change change change EDWARD M.FLETCHER,JR.

Attesting Officer? UNITED STATES PATENT OFFICE CERTIFiCATE OF CORRECTION appears in the above-identified patent are hereby corrected as shown below:

55, change "pin-shaped" to --apring- "pin-shaped" to ---spring-- "pin-shaped" to ---spr.i.ng--

"pim-shaped" to--spri ng-- "pin-shaped" to "pin-shaped to "pin-shaped" to "pin-shaped to --spring-'- -apring-- --:-apring'-- --spring-- WILLIAM E. SCHUYLER, JR. Commissioner of Patents 

